I
f screened cable is necessary
,
connect the cable screen on both ends
to ground potential
.
I
n the sensor
,
the screen must be connected
directly to the internal ground terminal
.
T
he ground terminal on the
outside of the housing must be connected to the potential equalisation
(
low impedance
).
I
f potential equalisation currents are expected
,
the connection on the
processing side must be made via a ceramic capacitor
(
e
.
g
.
1
n
F
,
1500
V
).
T
he low frequency potential equalisation currents are thus
suppressed
,
but the protective e
ff
ect against high frequency interfer
-
ence signals remains
.
W
arning
:
W
ithin galvanic plants as well as vessels with cathodic corrosion
protection there are considerable potential di
ff
erences
.
C
onsiderably
equalisation currents can be caused via the cable scrren when the
screen is earthed on both ends
.
T
o avoid this
,
the cable screen must
only connected to ground potential on one side of the switching
cabinet in such applications
.
T
he cable screen must
not
be connected
to the internal ground terminal in the sensor and the outer ground
terminal on the housing
not
to the potential equalisation
!
I
nformation
:
T
he metal parts of the instrument
(
antenna
,
transmitter
,
concentric
tube
,
etc
.)
are conductive connected with the inner and outer ground
terminal on the housing
.
T
his connection exists either directly metallic
or with instruments with external electronics via the screen of the
special connection cable
.
Y
ou can
fi
nd speci
fi
cations to the potential
connections within the instrument in chapter
"
T
echnical data
"
.
5
.
2
C
onnection
T
he connection of the voltage supply and the signal output is carried
out via the spring
-
loaded terminals in the housing
.
T
he connection to the indicating and adjustment module or to the
interface adapter is carried out via contact pins in the housing
.
P
roceed as follows
:
1
U
nscrew the housing cover
2
I
f an indicating and adjustment module is installed
,
remove it by
turning it slightly to the left
.
3
L
oosen compression nut of the cable entry
4
R
emove approx
.
10
cm
(
4
in
)
of the cable mantle
,
strip approx
.
1
cm
(
0
.
4
in
)
of insulation from the ends of the individual wires
C
able screening and
grounding
C
onnection technology
C
onnection procedure
26
VEGAPULS
62
•
4
…
20
m
A
/
HART
two
-
wire
5
C
onnecting to power supply
36503
-
EN
-
100607
